Generally, wheel- and-axle assemblies, of the character involved, incorporate two wheels and provide a relatively wide track, however, it is possible to provide on skate boards a single wheel supported on an axle, and thus provide a relatively narrow track, for example.
Although prior art skate board vehicles offer much versatility during use, and are continuously being improved, when skate board vehicles are used on a relatively steep slope, there exists the danger that the skate board, without the occupant thereon, to continue rolling down the slope, after the occupant has fallen or stepped off, and the run-away skate board vehicle both can inherently be the source of a dangerous accident to individuals and the like disposed downhill.